U.S. patent application number 14/161846 was filed with the patent office on 2014-08-14 for attraction plate structure of electromagnetic doorlock.
The applicant listed for this patent is YI-FAN LIAO. Invention is credited to YI-FAN LIAO.
Application Number | 20140225692 14/161846 |
Document ID | / |
Family ID | 50002597 |
Filed Date | 2014-08-14 |
United States Patent
Application |
20140225692 |
Kind Code |
A1 |
LIAO; YI-FAN |
August 14, 2014 |
ATTRACTION PLATE STRUCTURE OF ELECTROMAGNETIC DOORLOCK
Abstract
An attraction plate structure of electromagnetic doorlock
comprises an attraction plate positioned on a mounted body by a
positioning assembly. The attraction surface has an arch portion
higher than the bottom plane of 0.04 mm to 0.27 mm at a central
region thereof, and the arch portion extends towards both ends to
form an arc surface, so that a convex-curve surface is formed with
both ends lower than the central region. The present invention uses
the convex curve design of the attraction surface to produce the
curved internal stress while the attraction plate is pulled. Due to
the curved internal stress, the electric magnet under the normal
current is able to enhance the tensile value of the electromagnetic
doorlock, saving energy and enhancing the security access
control.
Inventors: |
LIAO; YI-FAN; (TAOYUAN
COUNTY, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LIAO; YI-FAN |
TAOYUAN COUNTY |
|
TW |
|
|
Family ID: |
50002597 |
Appl. No.: |
14/161846 |
Filed: |
January 23, 2014 |
Current U.S.
Class: |
335/279 |
Current CPC
Class: |
E05C 19/166 20130101;
H01F 7/1638 20130101 |
Class at
Publication: |
335/279 |
International
Class: |
H01F 7/16 20060101
H01F007/16 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 8, 2013 |
TW |
102105133 |
Claims
1. An attraction plate structure of electromagnetic doorlock,
comprising: an electric magnet; an attraction plate in a long
shape, having an attraction surface, the attraction surface
arranged at a corresponding surface of the electric magnet, and the
attraction plate positioned on a mounted body by a positioning
assembly; wherein the attraction surface has an arch portion higher
than the bottom plane of 0.04 mm to 0.27 mm at a central region
thereof, and the arch portion extends towards both ends to form a
curve surface, so that a convex-curve surface is formed with both
ends lower than the central region; whereby when the attraction
plate is attracted by the magnetic force produced by the electric
magnet, the convex-curve surface is forced to deform for abutting
the electric magnet ; when the mounted body is pulled in an
opposite direction of the electric magnet, the attraction plate
under the tension of the positioning assembly overcomes the curved
internal stress of the attraction plate to enhance the tensile
value of the attraction plate.
2. The attraction plate structure of electromagnetic doorlock as
claimed in claim 1, wherein the mounted body includes a box-like
body, U-shaped body, L-shaped body, flat body, or door plate.
3. The attraction plate structure of electromagnetic doorlock as
claimed in claim 2, wherein the mounted body has a positioning hole
in middle thereof, and the attraction plate corresponding to the
positioning hole has a spot-faced hole and the positioning assembly
is a countersunk bolt engaging into the spot-faced hole to fix the
attraction plate to the mounted body.
4. The attraction plate structure of electromagnetic doorlock as
claimed in claim 3, wherein the mounted body further has a pad
arranged between the bottom of the attraction plate and the mounted
body.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to an attraction plate structure of
electromagnetic doorlock, particularly to an attraction surface of
the attraction plate being a convex-curve surface structure to form
a curved internal stress.
[0003] 2. Description of the Related Art
[0004] In the access control monitoring system, the use of an
electromagnetic doorlock has been very popular. The electromagnetic
doorlock 10 as shown in FIG. 1 provides an electric magnet 11
mounted on a door flame 15 and an attraction plate 12 mounted on a
corresponding position of a door plate 14. When the electric magnet
11 is energized to produce electromagnetic attraction and attract
the attraction plate 12, the electromagnetic doorlock 10 forms in a
lock state. When the electric magnet 11 is de-energized and the
attraction plate 12 detaches from the electric magnet 11, the
electromagnetic door lock 10 then forms in an unlock state.
[0005] The traditional attraction plate 12 as FIGS. 2 to 4
comprises an attraction surface 121 in a flat shape, and one or two
positioning holes 122. The attraction plate 12 is fixed on a
mounted body 13 by a screw 123 and other related accessories 124.
The mounted body 13 as shown in FIG. 2 is in a box shape. With the
reference to FIG. 1A, the mounted body 13 has a plurality of fixed
holes 125 for fixed to the door plate 14 by a plurality screws 126,
but it is not a limitation. basically, the mounted body 13 can be
set for any shapes or the door plate 14 directly can be as a
mounted body 13 to fix the attraction plate 12 by the screw 123 and
other related accessories 124 as shown in FIG. 1B. No matter what
shape of the mounted body 13 is, the combination method of the
mounted body 13 and attraction plate 12 is the same, and the
attraction surface 121 is a plat surface. For example, the U.S.
Pat. No. 4,487,439 discloses a screw and a positioning hole, and
the U.S. Pat. No. 4,652,028 discloses tow screws and two
positioning holes.
[0006] This kind of structure of the attraction surface 121 is used
for many years. After continuous research, the inventor found out
that after the electric magnet 11 is energized, the magnetic flux
density (B) is strong in the region of both ends, and the magnetic
flux density (B) is weak in the middle region. Thus, as shown in
FIGS. 4 and 5A, 5B, when the door plate 144 is pulled, the action
force (F) is focus on the screw 123 in the middle, and the electric
plate 12 is pulled by the screw, 123. At this time, the middle
region of the electric plate 12 is curved and deformed like a
dotted line (C) as shown in FIG. 5B, and the curvature and
deformation will affect the attraction effect at both sides of the
electric plate 12. That is, when the region of the electric plate
12 is curved and deformed, the attraction surface 121 will departed
from the electric magnet 11. The experimental result shows that
when the electric magnet is subjected to 500 mA current and 12V
voltage, the electric magnet with strength of 185 mm and thickness
of 15 mm is easily to be pulled away from the attraction plate as
the tension value is between 400 to 500 pounds. The industry
claimed that the tension value can reach to 600 pounds, but the
attraction plate is pulled with less than 500 pounds. Therefore, to
increase the attraction force of the attraction plate 12 of the
conventional electromagnetic doorlock, the current of the electric
magnet 11 or the attraction area of the electric magnet and
attraction plate should be increased, forming a waste of energy or
increasing the materials and transportation costs. Accordingly,
there is room for improvement of the structure of conventional
attraction plate 12.
SUMMARY OF THE INVENTION
[0007] It is the main object of the present invention to provide an
attraction plate structure of electromagnetic doorlock so that
under the unchanged current of the electric magnet or unchanged
attraction area between the electric magnet and attraction plate,
the tension value is increased more than 10% to save energy and
enhance the security access control.
[0008] In order to achieve the above objects, the attraction plate
structure of electromagnetic doorlock comprises an electric magnet;
an attraction plate in a long shape, having an attraction surface,
the attraction surface arranged at a corresponding surface of the
electric magnet, and the attraction plate positioned on a mounted
body by a positioning assembly; wherein the attraction surface has
an arch portion higher than the bottom plane of 0.04 mm to 0.27 mm
at a central region thereof, and the arch portion extends towards
both ends to form a curve surface, so that a convex-curve surface
is formed with both ends lower than the central region;
[0009] Whereby when the attraction plate is attracted by the
magnetic force produced by the electric magnet, the convex-curve
surface is forced to deform for abutting the electric magnet; when
the mounted body is pulled in an opposite direction of the electric
magnet, the attraction plate under the tension of the positioning
assembly overcomes the curved internal stress of the attraction
plate to enhance the tensile value of the attraction plate.
[0010] Base on the features disclosed, the present invention uses
the convex curve design of the attraction surface to produce the
curved internal stress while the attraction plate is pulled. Due to
the curved internal stress, the electric magnet under the normal
current is able to enhance the tensile value of the electromagnetic
doorlock, saving energy and enhancing the security access
control.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a schematic view of a conventional electromagnetic
doorlock;
[0012] FIG. 1A is an exploded perspective view of the mounted body
of the conventional electromagnetic doorlock;
[0013] FIG. 1B is another exploded perspective view of the mounted
body of the conventional electromagnetic doorlock;
[0014] FIG. 2 is a perspective view of the separation of the
conventional electromagnetic doorlock;
[0015] FIG. 3 is a perspective view of the attraction state of the
conventional electromagnetic doorlock;
[0016] FIG. 4 is an exploded view of the attraction state of the
conventional electromagnetic doorlock;
[0017] FIG. 5A is a distribution diagram of an attraction force of
an attraction plate of the conventional electromagnetic
doorlock;
[0018] FIG. 5B is a deformation diagram of a tensile force of an
attraction plate of the conventional electromagnetic doorlock;
[0019] FIG. 6 is an exploded perspective view of the preferred
embodiment in accordance with the present invention;
[0020] FIG. 7 is an assembly perspective view of the preferred
embodiment in accordance with the present invention;
[0021] FIG. 8 is an assembly exploded view of the preferred
embodiment in accordance with the present invention;
[0022] FIG. 9 is an exploded perspective view of the preferred
embodiment in accordance with the present invention;
[0023] FIG. 10 is an exploded view of the attraction plate
structure in accordance with the present invention;
[0024] FIG. 11 is a partially enlargement view of FIG. 10;
[0025] FIG. 12 is a distribution diagram of an attraction force of
the attraction plate in accordance with the present invention;
[0026] FIG. 12A is comparison view between FIG. 12 of the present
invention and FIG. 5A of the prior art;
[0027] FIG. 13 is a deformation diagram of a tensile force of the
attraction plate in accordance with the present invention; and
[0028] FIG. 14 is a curved diagram of the tensile test of the
present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] With the referenced to FIGS. 6 through 14, an
electromagnetic doorlock 60 of the preferred embodiment in
accordance with the present invention comprises an electric magnet
20, and an attraction plate 30 in a long shape having an attraction
surface 31. The attraction surface 31 is arranged at a
corresponding surface of the electric magnet 20, and the attraction
plate 30 is positioned on a mounted body 40 by a positioning
assembly 50.
[0030] FIG. 9 is a sectional view of the attraction status of the
electric magnet 20 and attraction plate 30 in accordance with the
present invention; wherein the electric magnet 20 is fixed to a
door flame 15, and the attraction plate 30 is mounted on the
mounted body 40 which is fixed to a door plate 14. The
electromagnetic doorlock 60 in the embodiment basically has the
same mounted method with an electromagnetic door lock 10 of prior
art, and thus will not be described in details here. Also, the
electric magnet 20 is not the main feature of the present invention
and thus will not be described in details here. Besides, the
mounted body 40 disclosed in the present invention not limited to
the following shapes can be any shapes as required, or the door
plate 14 directly as the mounted body 40 is provided for
positioning the attraction plate 30.
[0031] The structure design of the attraction plate 30 is the main
feature of the present invention. With the reference to FIGS. 9 to
13, the important feature of the present invention is that the
attraction plate 30 is in an arch structure opposite to the
actuation position of a tensile force F of the attraction plate 30.
That is, the attraction plate 30 has middle region positioned to
the mounted body 40 by the positioning assembly 50, and the
attraction surface 31 is a convex-curve surface 33.
[0032] With the reference to FIGS. 10 and 11, the convex-curve
surface 33 higher the bottom plane L has a height h, and the height
h being a relative high point at the middle of an arch portion 32
extends towards both ends 34 to form an arc surface. The bottom
plane L here refers to a virtual straight line, a line for pulling
from the lowest position of both ends 34 of the attraction plate
30. The forming of the convex-curve surface 33 includes bending,
shaping, punching, planning and milling, and other processing
methods. Whereby when the attraction plate 30 is contacted to the
electric magnet 20, the attraction plate 30 with a curved internal
stress is attracted by the magnetic force of the electric magnet
20, and forced to deform rapidly for abutting the electric magnet
20 as shown in FIG. 9.
[0033] FIG. 12 is a distribution diagram of the magnetic flux
density B of the electric magnet 20 for the attraction plate 30,
and the reason for the magnetic flux density distribution is
explained in the prior art and thus will not be described here.
FIG. 12A is comparison view between FIG. 12 of the present
invention and FIG. 5A of the prior art, and FIG. 13 is a schematic
view, showing that the attraction plate 30 is not horizontal, and
the change of the convex-curve surface 33 by enlarging the
deformation curve to indicate that the tensile force is increased
by the curved internal stress.
[0034] The experiment proved that the height h of the convex-curve
surface 33 between 0.04 mm.about.0.27 mm can play a larger effect.
If the height h of the convex-curve surface 33 is too high, the
curved internal stress will be too large to offset the attraction
force of the electric magnet 20, and then decrease the tensile
force. From the material mechanics point of view, the attraction
plate 30 is like a ""-shaped beam, and both ends are positions with
stronger magnetic flux density B; thus, when the attraction plate
30 is pulled away from the electric magnet 20, the present
invention not only overcomes the magnetic force of the electric
magnet 20 but overcomes the curved internal stress S produced by
the ""-shaped attraction plate 30 as shown in FIG. 12. The curved
internal stress Si as shown in FIG. 13 gradually changes in
sequence from figure (a), (b) to (c). The figure (a) shows strong
curved internal stress S1 at middle of the attraction plate 30, and
then the strong curved internal stress S1 gradually becomes weak
curved internal stress S2 as shown in figure (b) for the tensile
force F is increased. Finally, the tensile force F continually
increases to the state as shown in the figure (c), so that the
attraction plate 30 can be pulled away from the electric magnet 20.
Therefore, the magnetic flux density B is weak in the middle region
of the conventional electric magnet 20 so that the attraction plate
30 is easy to be pulled away from the electric magnet 20. In
contrast, before overcoming the magnetic force as shown in FIG. 12,
the electric magnet 20 should overcomes the curved internal stress
S produced by the ""-shaped attraction plate 30 in the middle, and
this curved internal stress S just offsets the tensile force which
has weak magnetic flux density B at the middle of the attraction
plate 30. Accordingly, in the case of the constant input current of
the electric magnet 20, the electromagnetic doorlock 60 of the
present invention can increase the tension value by more than
10%.
[0035] In principle, as long as the positioning assembly 50 is able
to pull the middle of the attraction plate 30, the type of the
positioning assembly 50 is not a limitation. The mounted body 40
may include a box-like body, U-shaped body, L-shaped body, or flat
body. The above components can also be embedded in the door, or the
door is directly the mounted body 40. An applicable embodiment as
shown in FIGS. 6 to 9 is described below.
[0036] In the embodiment, the mounted body 40 being a box-like body
has a positioning hole 41 in a middle thereof, and the attraction
plate 30 corresponding to the positioning hole 41 has a spot-faced
hole 35, and the positioning assembly 50A is a countersunk bolt 50A
engaging into the spot-faced hole 35 to fix the attraction plate 30
to the mounted body 40. The mounted body 40 further has a pad 42
arranged between the bottom of the attraction plate 30 and the
mounted body 40.
[0037] To test and verify the effectiveness of the present
invention, the inventor uses the attraction plate of 185
mm.times.61 mm.times.12 mm to conduct the tensile test. The
following table shows the attraction plate after being energized of
500 mA current, and 12V voltage.
TABLE-US-00001 Tensile value Increased rate No. Attraction surface
(pound) of tensile value 1 NO convex-curve About 1076 -- surface 2
convex-curve surface About 1107 2.88% .uparw. (h): 0.02 mm 3
convex-curve surface About 1220 13.38% .uparw. (h): 0.04 mm 4
convex-curve surface About 1258 16.91% .uparw. (h): 0.06 mm 5
convex-curve surface About 1273 18.30% .uparw. (h): 0.09 mm 6
convex-curve surface About 1320 22.67% .uparw. (h): 0.12 mm 7
convex-curve surface About 1352 25.65% .uparw. (h): 0.15 mm 8
convex-curve surface About 1389 29.08% .uparw. (h): 0.18 mm 9
convex-curve surface About 1350 25.46% .uparw. (h): 0.21 mm 10
convex-curve surface About 1302 21.00% .uparw. (h): 0.24 mm 11
convex-curve surface About 1241 15.33% .uparw. (h): 0.27 mm 12
convex-curve surface About 1195 .dwnarw. (d): 0.29 mm 13
convex-curve surface About 1070 .dwnarw. (h): 0.30 mm
[0038] From the above test values, if the tensile position of
attraction plate is set in the middle without the convex-curve
surface 33 in the middle, the tensile value is about 1076 pounds.
If the tensile position of attraction plate 30 is at the middle
with the convex-curve surface 33 in the middle, there is no effect
while the height h of the convex-curve surface 33 is within 0.04
mm; however, the tensile value is significantly increased between
0.04 mm to 0.27 mm. FIG. 14 is a curve diagram drew according to
the present test, showing that the height h of the convex-curve
surface 33 between 0.09 mm to 0.24 mm has the best tensile value.
When the height h is over 0.27 mm, the curved internal stress will
be too large to offset the attraction force of the electric magnet
20, decreasing the tensile force, and forming an invalid area.
Therefore, from the above test values, the tensile value is
increased about 13.38% to 29.08% according to the different height
of the present invention.
[0039] The above test value uses the attraction plate of 185
mm.times.61 mm.times.12 mm; however, normal size of the attraction
plate mostly has length from 180 to 200 mm, and thickness from 11
to 16 mm. Therefore, different attraction plate has different
tensile value after test, but the corresponding increased rate of
tensile value and the curve tendency diagram basically has little
different. Thus, the attraction plate 30 under the same current,
the tensile value of the electromagnetic doorlock is increased at
least 10% to save energy and enhance the access control.
[0040] Although particular embodiments of the invention have been
described in detail for purposes of illustration, various
modifications and enhancements may be made without departing from
the spirit and scope of the invention.
[0041] Accordingly, the invention is not to be limited except as by
the appended claims.
* * * * *